1. Field of the Invention
The present invention generally relates to an identification card and, more particularly, to a switching means for a built-in type battery in an IC (integrated circuit) card that has a wide variety of applications.
2. Description of the Prior Art
Over the past few years, the use of personal cards issued from various credit card firms or banks have become increasingly more popular with which to buy articles without need of a cash transaction; therefore, recent years are called a card-age or a cashless-age. Hitherto, the card into which information has been stored by way of magnetization of a magnetic material is typical as such a kind of credit card. However, a memory capacity of information of this card is small and there is also a problem of identification of the card. Therefore, in recent years, an information card, i.e., what is called an IC card or intelligent card in which an integrated circuit consisting of a data processor, a data storage memory, and the like is built has been developed. According to this IC card, a very large amount of information can be stored and excellent identification can be obtained as compared with the conventional cards. In general, an EPROM (electrically programmable ROM) or a RAM (random access memory) is used as a memory to store information in the IC card. In the case of using the RAM, although the stored data can be extremely easily rewritten, it is necessary to equip a power backup battery or dry cell for this RAM in the IC card. However, in the power backup battery or dry cell built-in type card, it is a general manner to preliminarily power backup the RAM at the shipping stage of the card factory. Thus, drive current flows through the RAM from the shipping stage of the factory and the battery starts to be consumed. There is a problem such that as the time interval from the shipping of the factory until the IC card is given to the user is long, the effective period of time when the user can actually use the IC card is reduced.
The memory fabricated by using the CMOS technology of the power consumption saving type has recently been developed. However, not only the volume but also the electric power capacity of the battery which can be built in this kind of IC card (having a thickness of 0.8 mm as a standard size) is necessarily, extremely limited. Therefore, particularly, the above-mentioned problems are typical in the battery which must be built in such a thin card.
The present invention is made in consideration of the foregoing drawbacks. An object of the invention is to provide a battery built-in type identification card which can prevent the unwanted power consumption of the battery for power backup purposes and can prolong the effective use period of time of the identification card.